#!/usr/bin/perl
# 
# This is the master daemon that manages all periodically run processes on Striker dashboards and Anvil! 
# nodes.
#
# Exit codes;
# 0 = Normal exit
# 1 = md5sum of this program changed. Exited to reload.
# 
# TODO: 
# 

use strict;
use warnings;
use Anvil::Tools;
use Proc::Simple;

my $THIS_FILE           =  ($0 =~ /^.*\/(.*)$/)[0];
my $running_directory   =  ($0 =~ /^(.*?)\/$THIS_FILE$/)[0];
if (($running_directory =~ /^\./) && ($ENV{PWD}))
{
	$running_directory =~ s/^\./$ENV{PWD}/;
}

# Turn off buffering so that the pinwheel will display while waiting for the SSH call(s) to complete.
$| = 1;

my $anvil = Anvil::Tools->new({log_level => 2, log_secure => 1});

# Connect to the database(s). If we have no connections, we'll proceed anyway as one of the 'run_once' tasks
# is to setup the database server.
$anvil->Database->connect();
$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 2, secure => 0, key => "log_0132", variables => { "sys::db_connections" => $anvil->data->{sys}{db_connections} }});

# There are some things we only want to run on (re)start and don't need to always run.
run_once($anvil);

# Calculate my sum so that we can exit if it changes later.
$anvil->Storage->record_md5sums;

# Disconnect. We'll reconnect inside the loop
$anvil->Database->disconnect;
$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 2, secure => 0, key => "log_0132", variables => { "sys::db_connections" => $anvil->data->{sys}{db_connections} }});

# These are the things we always want running.
while(1)
{
	# Loop and sleep for 2s.
	keep_running($anvil);
	
	# Exit if called with '--run-once'
	if ($anvil->data->{switches}{'run-once'})
	{
		$anvil->nice_exit({code => 0});
	}
	
	# Has the file on disk changed?
	if ($anvil->Storage->check_md5sums)
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "warn", key => "message_0014"});
		$anvil->nice_exit({code => 1});
	}
	
	# Sleep now.
	sleep 2;
}

$anvil->nice_exit({code => 0});

#############################################################################################################
# Functions                                                                                                 #
#############################################################################################################

# These are tools that don't need to constantly run. They'll typically run when the server starts up or the
# daemon is restarted or reloaded.
sub run_once
{
	my ($anvil) = @_;
	
	# Check that the database is ready.
	my $shell_call = $anvil->data->{path}{exe}{'anvil-prep-database'};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { shell_call => $shell_call }});
	my $database_output = $anvil->System->call({shell_call => $shell_call, source => $THIS_FILE, line => __LINE__});
	if ($database_output)
	{
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { database_output => $database_output }});
	}
	
	return(0);
}

# These are tools that need to keep running.
sub keep_running
{
	my ($anvil) = @_;
	
	# Check for jobs that were running and now exited.
	if (exists $anvil->data->{processes})
	{
		foreach my $job_uuid (%{$anvil->data->{jobs}{handles}})
		{
			# If it's not a handle, delete it.
			my $running = $anvil->data->{jobs}{handles}{$job_uuid}->poll();
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 1, list => { 
				"jobs::handles::${job_uuid}" => $anvil->data->{jobs}{handles}{$job_uuid},
				running                      => $running, 
			}});
			
			# If it's not running, update the table to clear the 'job_picked_up_by' column.
			if (not $running)
			{
				my $exit_status = $anvil->data->{jobs}{handles}{$job_uuid}->exit_status();
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 1, list => { exit_status => $exit_status }});
				
				# Free up memory
				$anvil->data->{jobs}{handles}{$job_uuid}->cleanup();
				
				clear_job($anvil, $job_uuid);
			}
		}
	}
	
	# Update hardware state files.
	update_state_file($anvil);
	
	# Run any pending jobs by calling 'anvil-jobs' with the 'job_uuid' as a background process.
	run_jobs($anvil);
	
	return(0);
}

# This clears the 'job_picked_up_by'.
sub clear_job
{
	my ($anvil, $job_uuid) = @_;
	
	my $query = "
UPDATE 
    jobs 
SET 
    job_picked_up_by = '0', 
    modified_date    = ".$anvil->data->{sys}{use_db_fh}->quote($anvil->data->{sys}{db_timestamp})." 
WHERE 
    job_uuid         = ".$anvil->data->{sys}{use_db_fh}->quote($job_uuid)." 
";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { query => $query }});
	$anvil->Database->write({query => $query, source => $THIS_FILE, line => __LINE__});
	
	return(0);
}

# This will check for any jobs that aren't at 100%. For each found, if 'picked_up_by' is set, a check is made
# to see if the PID is still alive. If it isn't, or if 'picked_up_by' is not set, the appropriate tool is
# invoked to handle it.
sub run_jobs
{
	my ($anvil) = @_;
	
	# Get a list of pending or incomplete jobs.
	my $query = "
SELECT 
    job_uuid, 
    job_command, 
    job_data, 
    job_picked_up_by, 
    job_picked_up_at, 
    job_updated, 
    job_progress 
FROM 
    jobs 
WHERE 
    job_progress != 100 
AND 
    job_host_uuid = ".$anvil->data->{sys}{use_db_fh}->quote($anvil->Get->host_uuid)."
LIMIT 1;";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { query => $query }});
	
	my $results = $anvil->Database->query({query => $query, source => $THIS_FILE, line => __LINE__});
	my $count   = @{$results};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
		results => $results, 
		count   => $count,
	}});
	foreach my $row (@{$results})
	{
		my $job_uuid         =         $row->[0];
		my $job_command      =         $row->[1];
		my $job_data         = defined $row->[2] ? $row->[2] : "";
		my $job_picked_up_by =         $row->[3];
		my $job_picked_up_at =         $row->[4]; 
		my $job_updated      =         $row->[5];
		my $job_progress     =         $row->[6];
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
			job_uuid         => $job_uuid,
			job_command      => $job_command,
			job_data         => $job_data,
			job_picked_up_by => $job_picked_up_by,
			job_picked_up_at => $job_picked_up_at,
			job_updated      => $job_updated,
			job_progress     => $job_progress,
		}});
		
		# See if the job was picked up by another running instance.
		if ($job_picked_up_by)
		{
			# Check if the PID is still active.
			$anvil->System->pids({ignore_me => 1});
			
			### TODO: Add a check to verify the job isn't hung.
			# Skip if this job is in progress.
			next if exists $anvil->data->{pids}{$job_picked_up_by};

			# The previous job is gone, but the job isn't finished. Start it again.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "alert", key => "striker_warning_0007", variables => { 
				command => $job_command,
				pid     => $job_picked_up_by,
				percent => $job_progress, 
			}});
			clear_job($anvil, $job_uuid);
		}
		
		# Start the job, appending '--job-uuid' to the command.
		$anvil->data->{jobs}{handles}{$job_uuid} = $anvil->System->call({
			debug       => 2,
			background  => 1, 
			stdout_file => "/tmp/anvil.job.".$job_uuid.".stdout",
			stderr_file => "/tmp/anvil.job.".$job_uuid.".stderr", 
			shell_call  => $job_command." --job-uuid ".$job_uuid, 
			source      => $THIS_FILE, 
			line        => __LINE__});
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { "jobs::handles::${job_uuid}" => $anvil->data->{jobs}{handles}{$job_uuid} }});
		
		# Record the PID
		my $pid = $anvil->data->{jobs}{handles}{$job_uuid}->pid();
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { pid => $pid }});
		my $query = "
UPDATE 
    jobs 
SET 
    job_picked_up_by = ".$anvil->data->{sys}{use_db_fh}->quote($pid).", 
    modified_date    = ".$anvil->data->{sys}{use_db_fh}->quote($anvil->data->{sys}{db_timestamp})." 
WHERE 
    job_uuid         = ".$anvil->data->{sys}{use_db_fh}->quote($job_uuid)." 
";
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { query => $query }});
		$anvil->Database->write({query => $query, source => $THIS_FILE, line => __LINE__});
	}
	
	return(0);
}

# This calls 'anvil-update-states' which will scan the local machine's state (hardware and software) and
# record write it out to an HTML file 
sub update_state_file
{
	my ($anvil) = @_;
	
	my $shell_call = $anvil->data->{path}{exe}{'anvil-update-states'};
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { shell_call => $shell_call }});
	
	my $states_output = $anvil->System->call({shell_call => $shell_call, source => $THIS_FILE, line => __LINE__});
	if ($states_output)
	{
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { states_output => $states_output }});
	}
	
	return(0);
}